psemek/examples/audio.cpp

70 lines
1.3 KiB
C++

#include <psemek/audio/engine.hpp>
#include <psemek/audio/wave/sine.hpp>
#include <psemek/audio/wave/sawtooth.hpp>
#include <psemek/audio/wave/square.hpp>
#include <psemek/audio/wave/triangle.hpp>
#include <psemek/audio/mixer.hpp>
#include <psemek/app/app.hpp>
#include <psemek/app/main.hpp>
#include <map>
using namespace psemek;
static std::map<SDL_Keycode, int> const key_to_midi
{
{SDLK_a, 69},
{SDLK_s, 70},
{SDLK_d, 71},
{SDLK_f, 72},
{SDLK_g, 73},
{SDLK_h, 74},
{SDLK_j, 75},
{SDLK_k, 76},
{SDLK_l, 77},
{SDLK_SEMICOLON, 78},
{SDLK_QUOTE, 79},
};
struct audio_app
: app::app
{
audio_app()
: app::app("Audio example")
{
mixer_ = audio::make_mixer();
engine_.output(mixer_);
}
void on_key_down(SDL_Keycode key) override
{
app::app::on_key_down(key);
if (key_to_midi.contains(key) && !channels_.contains(key))
{
int midi = key_to_midi.at(key);
channels_[key] = mixer_->add(audio::sine_wave(440.f * std::pow(2.f, (midi - 69) / 12.f)));
}
}
void on_key_up(SDL_Keycode key) override
{
app::app::on_key_up(key);
if (channels_.contains(key))
{
channels_[key]->stop();
channels_.erase(key);
}
}
private:
audio::engine engine_;
audio::mixer_ptr mixer_;
std::map<SDL_Keycode, audio::mixer::channel_ptr> channels_;
};
int main()
{
return app::main<audio_app>();
}